I pretty much do not carry grudges, long term or otherwise. People are only humans, and we all make mistakes, and some of those mistakes do hurt other people really bad. I sincerely hope that people whom I have hurt will forgive me, at least eventually, and so I do my best to forgive people who have hurt me, and not carry it around in my life. If for no other reason, carrying a grudge is bad for the person who is carrying it around, and it stops you from enjoying life. It is equally important not to trust people who have proven that they can’t be trusted, so I do my best to forgive but not put myself in the same situation again.
There are a few companies I won’t do business with again but real grudges, no. Forgive and forget is much healthier and happier.
Recently at a group brunch, a long time friend lit into me with both barrels on an animal related issue. I had returned a cat to the Humane society as per the contract. That led her to my sale of one of the ponies we had 35 years ago. She has just been an angry person. Most of my group was ready to hang her for my sake. It didn't really bother me. She is where she is and I am where I am. But we were surprised. 35 years?